Cemented Carbide Composition for Chipping-Resistant Stainless Cutting

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing cemented carbide alloys for cutting tools face challenges in achieving high plastic deformation resistance and chipping resistance, particularly when used for cutting stainless steel.

Innovation Solution

A cemented carbide alloy composition with controlled grain sizes and specific metal component ratios, including 5.0 to 15.0% Co and Ni, 4.0 to 12.0% Ti, Zr, Nb, and Ta, and 5.4 to 6.5% C, with y phases having uniform metal atom distributions and controlled standard deviations, enhances resistance to plastic deformation and chipping.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional cemented carbide alloy compositions are used, then production cost is reduced by replacing expensive Ta with cheaper Nb and Zr, but plastic deformation resistance and chipping resistance deteriorate

Engineering Contradiction:
Improveproduction costVSAvoidplastic deformation resistance and chipping resistance
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The patent applies parameter changes by precisely controlling the composition ranges of multiple elements (Co: 3-15 mass%, Ni: 2-15 mass%, Ti: 3-12 mass%, Zr: 2-12 mass%, Nb: 3-15 mass%, Ta: 2-10 mass%) and the grain size distribution of y phases (1.0-4.0 μm average with specific standard deviation constraints). This systematic parameter optimization enables the alloy to achieve both cost-effectiveness through reduced Ta content and superior mechanical properties through balanced composition control.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent employs composite materials by creating a multi-phase microstructure consisting of hard phases (WC, TiC, ZrC, NbC, TaC), binder phases (Co, Ni), and y phases with specific composition ratios. The y phases contain controlled combinations of Ti, Zr, Nb, Ta, and W in specific proportions, forming a composite structure that synergistically provides both economic efficiency and enhanced plastic deformation resistance and chipping resistance.

Inventive Principle:
Principle #40Composite materials

2Reliability

If Ta content is increased to improve chipping resistance, then production cost increases, but if Ta is replaced with cheaper elements, then chipping resistance decreases

Engineering Contradiction:
Improvechipping resistanceVSAvoidproduction cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent applies merging by combining multiple elements (Ti, Zr, Nb, Ta, W) in the y phases with specifically controlled composition ratios and uniform distributions. This synergistic combination allows the alloy to achieve chipping resistance comparable to or exceeding high-Ta formulations while using a more balanced, cost-effective mix of elements, thereby reducing production cost without sacrificing reliability.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4692393A1Cemented carbide for cutting tool and cutting tool using same
Publication Date: 2026.02.11 MITSUBISHI MATERIALS CORP
  • EP4692393A1 patent drawingFigure 1~2
  • EP4692393A1 patent drawingFigure 3
  • EP4692393A1 patent drawing

AI summary

A cemented carbide alloy for cutting tools comprises a hard phase having an average grain size in a range of 0.5 to 4.0 µm and a y phase having an average grain size in the range of 1.0 to 4.0 µm. The y phases each comprise Ti, Zr, Nb, Ta, and W in percentages a, b, c, d, and e, respectively, where a + b + c + d + e = 100.0, and their average values aavg, bavg, cavg, davg, and eavg, where aavg + bavg + cavg + davg + eavg = 100.0, in all the measured y phases satisfy the relations: 20.0 ≤ aavg ≤ 30.0, 20.0 ≤ bavg ≤ 30.0, 10.0 ≤ cavg ≤ 20.0, 20.0 ≤ davg ≤30.0, and 5.0 ≤ eavg ≤ 15.0. The average of the respective standard deviations σa σb, σc, σd, and σe, of the percentage a, b, c, d, and e is 0.40 or less.